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Improve mutable/immutable comment, add `make-vector' example.

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Eli Barzilay 2013-07-16 03:06:11 -04:00
parent 159b7e4e1e
commit 547a8a6db1
1 changed files with 6 additions and 3 deletions
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racket.html.markdown
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@ -365,13 +365,16 @@ n ; => 6
(set-box! n* (add1 (unbox n*)))
(unbox n*) ; => 6
;; Many Racket datatypes can be immutable or mutable
;; (Pairs, Lists, Strings, Vectors, Hash Tables, etc...)
;; Many Racket datatypes are immutable (pairs, lists, etc), some come in
;; both mutable and immutable flavors (strings, vectors, hash tables,
;; etc...)
;; Use `vector' to create a mutable vector
;; Use `vector' or `make-vector' to create mutable vectors
(define vec (vector 2 2 3 4))
(define wall (make-vector 100 'bottle-of-beer))
;; Use vector-set! to update a slot
(vector-set! vec 0 1)
(vector-set! wall 99 'down)
vec ; => #(1 2 3 4)
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